https://doi.org/10.25678/0000dd

Data for: Beyond signal quality: The value of unmaintained pH, dissolved oxygen, and oxidation-reduction potential sensors for remote performance monitoring of on-site sequencing batch reactors

Sensor maintenance is time-consuming and is a bottleneck for monitoring on-site wastewater treatment systems. Hence, we compare maintained and unmaintained sensors to monitor the biological performance of a small-scale sequencing batch reactor (SBR). The sensor types are ion-selective pH, optical dissolved oxygen (DO), and oxidation-reduction potential (ORP) with platinum electrode. We created soft sensors using engineered features: ammonium valley for pH, oxidation ramp for DO, and nitrite ramp for the ORP. Four soft sensors based on unmaintained pH sensors correctly identified the completion of the ammonium oxidation (89 to 91 out of 107 cycles), about as many times as soft sensors based on a maintained pH sensor (91 out of 107 cycles). In contrast, the DO soft sensor using data from a maintained sensor showed slightly better (89 out of 96 cycles) detection performance than that using data from two unmaintained sensors (77, respectively 82 out of 96 correct). Furthermore, the DO soft sensor using maintained data is much less sensitive to the optimisation of cut-off frequency and slope tolerance than the soft sensor using unmaintained data. The nitrite ramp provided no useful information on the state of nitrite oxidation, so no comparison of maintained and unmaintained ORP sensors was possible in this case. We identified two hurdles when designing soft sensors for unmaintained sensors: i) Sensors’ type- and design-specific deterioration affects performance. ii) Feature engineering for soft sensors is sensor type specific, and the outcome is strongly influenced by operational parameters such as the aeration rate. In summary, the results with the provided soft sensors show that frequent sensor maintenance is not necessarily needed to monitor the performance of SBRs. Without sensor maintenance monitoring smalls-scale SBRs becomes practicable, which could improve the reliability of unstaffed on-site treatment systems substantially.

Data and Resources

Citation

This Data Package

Schneider, M. Y., Carbajal, J. P., Furrer, V., Sterkele, B., Maurer, M., & Villez, K. (2019). Data for: Beyond signal quality: The value of unmaintained pH, dissolved oxygen, and oxidation-reduction potential sensors for remote performance monitoring of on-site sequencing batch reactors [Data set]. Eawag: Swiss Federal Institute of Aquatic Science and Technology. https://doi.org/10.25678/0000DD

The associated article

Schneider, M. Y., J. P. Carbajal, V. Furrer, B. Sterkele, M. Maurer, and K. Villez (2019), Beyond signal quality: The value of unmaintained pH, dissolved oxygen, and oxidation-reduction potential sensors for remote performance monitoring of on-site sequencing batch reactors, Water Research, 161, 639–651, doi:10.1016/j.watres.2019.06.007.

Metadata

  Publication Data Package for:
Open Data Open Data
Author(s)
  • Schneider, Mariane Yvonne
  • Sterkele, Bettina
  • Furrer, Viviane
  • Richter, Sylvia
  • Rottermann, Karin
Keywords unmaintained sensors,sequencing batch reactor,monitoring,wastewater treatment
Substances (scientific names)
  • Ammonium nitrogen (QGZKDVFQNNGYKY-UHFFFAOYSA-O)
  • Nitrate nitrogen (NHNBFGGVMKEFGY-UHFFFAOYSA-N)
  • Nitrite nitrogen (IOVCWXUNBOPUCH-UHFFFAOYSA-M)
Substances (generic terms)
  • nutrients
  • organic carbon
Systems
  • two population equivalent wastewater treatment plant
Timerange
  • 2017-05 TO 2018-05
Review Level general
Curator Schneider, Mariane
Contact mariane.schneider@eawag.ch
DOI 10.25678/0000dd